초록 |
Over many past years, area-selective atomic layer deposition (AS-ALD) has been developed for fabricating 3D nanostructures. Since ALD is a surface sensitive deposition technique, surface modification of substrate renders the deposition of films to be area-selective. Most previous studies on AS-ALD have utilized self-assembled monolayer (SAM), which inhibits the chemical reaction between substrate and precursors, so that the film cannot grow on SAM-coated area. Although Al2O3 has been widely used for ALD, there is no experimentally sucessful report on fabricating Al2O3 nanopattern by AS-ALD based on SAM. Rather, a previous report on the calculation of surface reactions between trimetylaluminum (TMA) and SAM by density functional theory (DFT) has been presented. That paper describes that CH3-terminated SAM shows no thermodynamic driving force for the reaction between them, leading to AS-ALD Al2O3 by using TMA. In following study, however, CH3-terminated SAMs could not block Al2O3 deposition. Although there is discrepancy between theoretical observation and experimental results and it is very important for future nanoscale patterning technology, fundamental study of AS-ALD Al2O3 on SAM has not been reported. In this presentation, I introduce the recent trend of AS-ALD and reaction mechanism of AS-ALD Al2O3 by experimental results together with calculaion study. Finally I introduce one example to obtain sucessful nanopattern of Al2O3 by AS-ALD with SAMs as controlling process conditions properly. This fundamental research on surface chemistry of reaction of AS-ALD Al2O3 presents opportunities to explore nanoscale patterning technology towards realizing electronic nanoscale devices. |